It is incumbent on the court to guarantee defendants know why they are arrested and to provide them a chance to talk to attorneys:

"In this case, we have not been able to really meet those expectations," Román said.

So far, the court is within the acceptable timeframe set by the rules of criminal procedure, according to documents. A Dec. 16 status conference before Judge James Keppel has been set.

Mesa police arrested Perez on April 22 after a 17-year-old girl told police he put a pillow over her chest, held her down and raped her, according to court documents.

At the time, an police officer who only spoke intermediate Spanish "detected no unusual dialect" and he communicated with Perez well enough to build a detailed statement of probable cause.

"In his professional opinion, the defendant understood what he told him and he understood what the defendant told him," said a police spokesman, Sgt. Chuck Trapani.

Court officials gathered financial information on Perez.

According to the documents, his total monthly expenses are $800. He works in construction and lives in Mesa. The paperwork established that he "stated he wants to return to Mexico."

Language experts suggest Perez may speak only fragmented Spanish, insufficient to understand interrogation questions and then assist counsel in his defense.

A Superior Court judge has postponed Perez's legal proceedings as court officials hunt the nation for interpreters who know his native tongue. The Mexican Consul and linguists from Texas to California have worked the case.

They were able to understand a few words, "mother and father," and they determined he lived in southern Mexico at one time, Román says.

At one point, they thought they discovered Perez's native tongue: a dialect of Tzotzil. It's one of about 20 Mayan-based languages spoken in poor, pre-modern areas of southern Mexico and parts of Guatemala, said Emil Volek, a professor of Spanish at Arizona State University.

But now they believe he speaks Northern Mam, another Mayan dialect. A linguist next week will try to communicate with Perez using the language that's spoken by a few thousand in Mexico and about 200,000 in Guatemala.

Southern Mexico and parts of Central America are home to an estimated 70 indigenous groups.

Many are isolated and resemble pre-conquest societies, experts say.

"There might not be anyone who can speak the language of this person at the level required for court interpreting," said Dr. Roseann Dueñas Gonzalez, director of the National Center for Interpretation and professor of English at the University of Arizona.

"You have a person unable to have the benefit of justice. And you have a government that's unable to seek justice because they have a (language) barrier."